How can I render the entire video in Blender VSE?
You need to change the End Frame in the render settings.

If you are rendering at 24 frames per second, and since you have a 3 minute video you will need to set the End Frame to 4320.

You also will want to change the render Resolution (it is right next to the frame range), now you have it set to 960x540, full HD is 1920x1080 but with the scale set to 100%.
Read the video Encoding section of the blender manual for more information, or the 2.79 manual page.